Patent 8672575 was granted and assigned to Renishaw plc on March, 2014 by the United States Patent and Trademark Office.
A pivot joint has a first member having a ball located at one end, a fixed member having one or more bearing surface, which locates on the ball of the first member and a second member having one or more bearing surface located at one end which locates onto the ball of the first member. The first and second members are rotatable about the center of the ball. This type of pivot joint is suitable for use in a machine such as a Stewart platform.